Various types of devices and methods are known in the art for measuring the intensity of ionizing radiation. One important application of such devices and methods is in evaluating levels of radiation to which people may be exposed and warning against excessive exposure to radiation. Geiger counters and film badges, for example, have been widely used for such purposes for many years.
Portability can be an important consideration in the design of a radiation detector. For example, U.S. Patent Application Publication 2008/0173820, whose disclosure is incorporated herein by reference, describes a portable radiation detection apparatus, which transforms detected radioactivity into an analog pulse signal and then converts the analog pulse signal into a digital pulse signal, which is counted. The apparatus is said to provide low cost and wireless communication, as well as distance protection for radiation protection personnel.
WikiSensor Dosimeter is a an application for smart phones for measuring radioactivity. According to information provided at wikisensor.com, the cameras lenses found on most smart phones are sensitive not only to visible light, but also to other types of waves including gamma and X-rays emitted by radioactive sources. When the camera is covered with something opaque (such as electrical tape or the thumb of the user), the lens no longer captures visible light, but only gamma and X-rays. The application algorithm counts the number of impacts received and translates it into a value in microsieverts per hour.
As another example, the iRad® Geiger, offered by Creative Electron, Inc. (Carlsbad, Calif.), is said to transform an iPhone, iPad, iPod, or Android device into a radiation detector instrument. The battery-free iRad Geiger has an interface to the audio jack to harvest energy from the smart phone. An application allows users to measure, log, alarm, and map their radiation measurements.
The information presented above is intended to give a general overview of the present state of the art in the field of the invention, and should not be considered an admission that the publication and products cited here may be considered in any way to be prior art against the invention described in this patent application.